The%20III%20nerve%20palsy:%20when%20to%20panic - PowerPoint PPT Presentation

Title: The%20III%20nerve%20palsy:%20when%20to%20panic


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The III nerve palsy when to panic

• UBC Clinical neuroophthalmology day - 18 November
  2005
• Jason Barton

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III nerve palsies
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Nuclear III palsy bilateral superior rectus
weakness, bilateral ptosis, bilateral pupil
paresis
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39 year old man with HIV/AIDS, presenting with
headache and bilateral ptosis. Exam showed
limited downgaze od more than os, and bilateral
ptosis. Autopsy showed HIV encephalitis
surrounding the aqueduct.
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Fascicular III palsy may mimic divisional
palsies, monocular elevation paresis, or
isolated paresis of the pupil or inferior
oblique ipsilateral limb ataxia (brachium
conjunctivum) contralateral resting
tremor/chorea/ballismus (red nucleus) contralater
al paresis of the limbs and/or face (cerebral
peduncle) vertical supranuclear palsy (riMLF,
inC) drowsiness Causes of midbrain III
syndromes vascular 'top of the basilar'
syndromes. intrinsic primary or secondary
tumors infections (AIDS, TB) demyelination brai
nstem hemorrhages (including uncal herniation)
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Bilateral fascicular III palsies 68 year old man
with hypertension, awoke with bilateral
ptosis. Exam 0 elevation and 0 depression ou,
50 adduction od and 0 adduction os. Severe
ptosis 6mm lid fissure od and 4mm os, with
frontalis contraction. Pupils 4mm od and 2.5mm
os, with light reaction. Left leg paresis.
MRI with DWI
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Peripheral III palsy subarachnoid portion
contralateral hemiparesis. Meningismus
depending on etiology. Causes Aneurysms
basilar or ICA-pcomm artery Ischemia
hypertension/DM. sildenafil/cocaine, GCA,
carotid occlusion. Trauma LOC or skull
fractures, uncal herniation Tumors
neurinomas and schwannomas Inflammation Lyme,
sarcoidosis - rare.
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Complete III palsy with ICA-pcomm aneurysm
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Woman anticoagulated for atrial fibrillation with
right temporal lobe and capsular stroke, returned
1 year later with new right III palsy. 1.5 years
later, showed signs of aberrant regeneration also
(elevation accompanied by adduction).
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Peripheral III palsy Cavernous sinus lesions
divisional paresis IV V and VI, but can cause
III mononeuropathies. Causes Vascular dural
arteriovenous malformations, giant ICA
aneurysm Tumours 1 - meningioma, chordoma,
craniopharyngioma, 2 - nasopharyngeal
ca Vascular/tumour pituitary apoplexy
! Inflammation viral or flu-like infections,
sphenoid sinusitis
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Woman with known metastatic breast cancer
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Aneurysms basilar or ICA-pcommA
aneurysms usually acute painful palsy.
Natural history - Soni, JNNP 1974 rupture
of ICA-PCA aneurysms preceded by warning sign 70
of time. average time between initial symptoms
and subarachnoid hemorrhage 30 days.  delay
in treating ICA-PCA aneurysm increases mortality
from 20 to 67.
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Best way to detect an aneurysm? (Can we avoid
1-2 risks of formal angiography?) CTA and MRA
detect aneurysms of 4-5mm. Is that good
enough? -Yanaka et al, Neurosurg 2003 aneurysms
of 4-8mm can present with III palsy -Jacobson
Trobe, AJO 1999 MRA would miss lt 1.5 of
aneurysms with III palsy Is the prognosis of
small ICA-PCA aneurysms with III palsy better
than large ones? For asymptomatic aneurysms,
risk of SAH size and location. NEJM 2004
lt10mm 0.05/yr, pcomm relative risk 8X that
of other aneurysms. unlikely that surgery will
reduce the rates of disability and death in
patients with unruptured aneurysms smaller than
10mm in diameter and no history of subarachnoid
hemorrhage. Unknown does this same
conclusion hold for ICA-PCA aneurysms with
symptoms from compression of III nerve rather
than SAH?
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Ischemic palsies mean age of 61 years
microvascular palsy presents as a sudden onset
painful III nerve defect with frequent sparing of
the pupil. in many, diabetes is discovered
after the III nerve palsy.  time course 1.
Some progression is commonly in the first 1-3
weeks. 2. Pain should not last more than 7-14
days. If it does, worry. 3. Recovery 1 to 3
months later. If not, image for tumors/aneurysms.
4. Spontaneous recovery can happen after weeks/
months with p-comm aneurysms and lymphoma.
Recovery with compression or trauma can even
occur after several years.
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• Three rules to remember
• The pupil rule complete pupil sparing with
  complete EOM involvement is not going to be from
  an aneurysm

(after Lee et al, Survey of Ophthalmology 2002)
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66 year old man with longstanding DM,
pupil-sparing complete III palsy, with pain for 1
week. Recovered after 3 months.
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• Three rules to remember
• The pupil rule complete pupil sparing with
  complete EOM involvement is not going to be from
  an aneurysm.
• Aberrant regeneration - implies compression until
  proven otherwise

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III nerve palsy with aberrant regeneration caverno
us sinus meningioma
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• Three rules to remember
• The pupil rule complete pupil sparing with
  complete EOM involvement is not going to be from
  an aneurysm.
• Aberrant regeneration - implies compression until
  proven otherwise
• Divisional palsies - think cavernous sinus mass

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Inferior divisional III palsy
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• III nerve palsy summary
• 1. Can you locate the site of damage?
• (i) Does it localize a nuclear site?
• (ii) Are there neighbourhood neurologic signs?
• 2. Do the three rules suggest an aneurysm or
  mass?
• (i) pupil rule
• (ii) aberrant regeneration rule
• (iii) divisional palsy rule
• If it is suspicious,
• MRI/CT sella with contrast, CTAngiogram
• If negative but high index of suspicion,
• formal angiogram, and dont forget CSF in
  appropriate cases